15be242b3a
libraries contain stubs only (with minor exceptions a la pipe(2)), the purpose of this section is to provide linkage information.
135 lines
4.0 KiB
Groff
135 lines
4.0 KiB
Groff
.\" $NetBSD: msync.2,v 1.13 1999/12/02 21:42:38 kleink Exp $
|
|
.\"
|
|
.\" Copyright (c) 1991, 1993
|
|
.\" The Regents of the University of California. All rights reserved.
|
|
.\"
|
|
.\" Redistribution and use in source and binary forms, with or without
|
|
.\" modification, are permitted provided that the following conditions
|
|
.\" are met:
|
|
.\" 1. Redistributions of source code must retain the above copyright
|
|
.\" notice, this list of conditions and the following disclaimer.
|
|
.\" 2. Redistributions in binary form must reproduce the above copyright
|
|
.\" notice, this list of conditions and the following disclaimer in the
|
|
.\" documentation and/or other materials provided with the distribution.
|
|
.\" 3. All advertising materials mentioning features or use of this software
|
|
.\" must display the following acknowledgement:
|
|
.\" This product includes software developed by the University of
|
|
.\" California, Berkeley and its contributors.
|
|
.\" 4. Neither the name of the University nor the names of its contributors
|
|
.\" may be used to endorse or promote products derived from this software
|
|
.\" without specific prior written permission.
|
|
.\"
|
|
.\" THIS SOFTWARE IS PROVIDED BY THE REGENTS AND CONTRIBUTORS ``AS IS'' AND
|
|
.\" ANY EXPRESS OR IMPLIED WARRANTIES, INCLUDING, BUT NOT LIMITED TO, THE
|
|
.\" IMPLIED WARRANTIES OF MERCHANTABILITY AND FITNESS FOR A PARTICULAR PURPOSE
|
|
.\" ARE DISCLAIMED. IN NO EVENT SHALL THE REGENTS OR CONTRIBUTORS BE LIABLE
|
|
.\" FOR ANY DIRECT, INDIRECT, INCIDENTAL, SPECIAL, EXEMPLARY, OR CONSEQUENTIAL
|
|
.\" DAMAGES (INCLUDING, BUT NOT LIMITED TO, PROCUREMENT OF SUBSTITUTE GOODS
|
|
.\" OR SERVICES; LOSS OF USE, DATA, OR PROFITS; OR BUSINESS INTERRUPTION)
|
|
.\" HOWEVER CAUSED AND ON ANY THEORY OF LIABILITY, WHETHER IN CONTRACT, STRICT
|
|
.\" LIABILITY, OR TORT (INCLUDING NEGLIGENCE OR OTHERWISE) ARISING IN ANY WAY
|
|
.\" OUT OF THE USE OF THIS SOFTWARE, EVEN IF ADVISED OF THE POSSIBILITY OF
|
|
.\" SUCH DAMAGE.
|
|
.\"
|
|
.\" @(#)msync.2 8.2 (Berkeley) 6/21/94
|
|
.\"
|
|
.Dd October 10, 1997
|
|
.Dt MSYNC 2
|
|
.Os
|
|
.Sh NAME
|
|
.Nm msync
|
|
.Nd synchronize a mapped region
|
|
.Sh LIBRARY
|
|
.Lb libc
|
|
.Sh SYNOPSIS
|
|
.Fd #include <sys/mman.h>
|
|
.Ft int
|
|
.Fn msync "void *addr" "size_t len" "int flags"
|
|
.Sh DESCRIPTION
|
|
The
|
|
.Fn msync
|
|
system call writes all pages with shared modifications
|
|
in the specified
|
|
region of the process's address space back to permanent
|
|
storage, and, if requested, invalidates cached data mapped
|
|
in the region.
|
|
If
|
|
.Fa len
|
|
is 0, all modified pages within the region containing
|
|
.Fa addr
|
|
will be flushed;
|
|
if
|
|
.Fa len
|
|
is non-zero, only modified pages containing
|
|
.Fa addr
|
|
and
|
|
.Fa len
|
|
succeeding locations will be flushed.
|
|
Any required synchronization of memory caches
|
|
will also take place at this time.
|
|
Filesystem operations on a file that is mapped for shared modifications
|
|
are unpredictable except after an
|
|
.Fn msync .
|
|
.Pp
|
|
The
|
|
.Fa flags
|
|
argument is formed by
|
|
.Em or Ns 'ing
|
|
the following values
|
|
.Pp
|
|
.Bl -column -offset indent -compact MS_INVALIDATE
|
|
.It Dv MS_ASYNC Ta Perform asynchronous writes.
|
|
.It Dv MS_SYNC Ta Perform synchronous writes.
|
|
.It Dv MS_INVALIDATE Ta Invalidate cached data after writing.
|
|
.El
|
|
.Sh ERRORS
|
|
The following errors may be reported:
|
|
.Bl -tag -width Er
|
|
.It Bq Er EBUSY
|
|
The
|
|
.Dv MS_INVALIDATE
|
|
flag was specified and a portion of the specified region
|
|
was locked with
|
|
.Xr mlock 2 .
|
|
.It Bq Er EINVAL
|
|
The specified
|
|
.Fa flags
|
|
argument was invalid.
|
|
.It Bq Er EINVAL
|
|
The
|
|
.Fa addr
|
|
parameter was not page aligned.
|
|
.It Bq Er EINVAL
|
|
The
|
|
.Fa addr
|
|
parameter did not specify an address part of a mapped region.
|
|
.It Bq Er EINVAL
|
|
The
|
|
.Fa len
|
|
parameter was negative.
|
|
.It Bq Er EIO
|
|
An I/O error occured while writing to the file system.
|
|
.It Bq Er ENOMEM
|
|
Addresses in the specified region are outside the range allowed
|
|
for the address space of the process, or specify one or more pages
|
|
which are unmapped.
|
|
.El
|
|
.Sh SEE ALSO
|
|
.Xr mlock 2 ,
|
|
.Xr mmap 2 ,
|
|
.Xr munlock 2
|
|
.Sh BUGS
|
|
Writes are currently done synchronously even if the
|
|
.Dv MS_ASYNC
|
|
flag is specified.
|
|
.Sh HISTORY
|
|
The
|
|
.Fn msync
|
|
function first appeared in
|
|
.Bx 4.4 .
|
|
It was modified to conform to
|
|
.St -p1003.1b-93
|
|
in
|
|
.Nx 1.3 .
|
|
.P
|